EVOLUTION: THE TASMANIAN ISOPOD

Mount Wellington, home of the isopod studied in Tasmania

Isopods are common marine, freshwater, and terrestrial animals with seven pairs of legs.  The one most familiar to you is probably the one that rolls up in a ball when disturbed after you pick up your flower pot.  Most are flattened so top and bottom appear close together.  But the one in Tasmania is part of an extremely old group and does not have that flattening, in fact it appears as though it is flattened with the sides closer together.

Mount Wellington is a little over 4,000 feet tall.  The summit is only a few miles from downtown Hobart, as shown from the harbor on the Derwent River below.  Darwin had difficulty reaching the summit, which he did late in the day on his second try.  It was much easier for me because a road had been built to very close to the summit.  The back side of the mountain still has tree ferns as noted by Darwin in his Voyage of the Beagle along the Northwest Bay River which is fed by the mountain top pools.

The isopods on Mount Wellington and others in the same suborder are now restricted to the Southern Hemisphere.  Although first discovered in well water in New Zealand, most species are found in Tasmania, with only three in South Africa.  Their discovery came after Darwin's visit to Tasmania and Mount Wellington where he may have trod through the pools where they are found as he gazed out from the summit and saw the views below.

What looks like moss covered rock is really the dense growth of branches of a composite noted below.

The pools around the round green composite Abrotenella fosteroides in the first picture closeup were sampled periodically for a year.

This view from just beyond the pool containing the isopods shows Ralph's Bay and the Tasman Peninsula to the East of the summit lookout.

At least a three year life cycle from egg to isopod to egg

All the isopods in one kitchen strainer scoop were collected, counted, and measured.  During the Australian summer they were inactive in the dried but damp pools.  When pools refilled in the spring, a new batch of young were released from the brood pouch (formed from plates extending from basal segments of four pair of legs) for the annual crop of young.  A maximum of 19 young or eggs were counted in pouches from other samples.

If you notice carefully you can see two or three age classes in the November sample. In the May sample only two of the young from the previous date were included as the new young became quite numerous.   A possible middle group from November is merging with the adults.  Relatively few adults were found in the July sample, although in August they were abundant.  Part of the disparity of adult numbers was probably due to the fact that many females with eggs were abundant under the green composite shown, while my samples came from the flocculent sediment in the deeper part of the pool.

The pools were above the timber line on the mountain and had snow and ice part of the winter.  But it did not appear a factor in reducing the number of generations to one per year because a population of closely related isopods had the same growth pattern at sea-level on nearby Bruny Island.  Just for the record for interested zoologists, the isopod is Colubotelson thomsoni in the suborder Phreatoicoidea.  It is usually viewed from the side because the flattening make a specimen lay in that position as in the photo above and the figure below.

The pleopods beat in a channel made by downward projections of the sides of the abdominal plate.  They are the respiratory organs of the isopod, although in the male a portion of the second one is modified for sperm transfer.  This region of the abdomen retains the segmented nature whereas in the Michigan isopod (Asellus) the segments of the exoskeleton are fused.  Because of the flattening, its pleopods are exposed and the third one has a protective plate shielding the ones behind it.  The first two, unprotected are greatly reduced but the sperm transfer appendage of the male is still functional.  So both sexes have the respiratory function of the first two pleopods lost by selection driven by the selective value of the arrangement for the male.

The eggs of the Tasmanian isopod have about twice the diameter of the Michigan ones.  The egg shell is also about twice as thick.  Development to hatching takes several months in contrast to about two weeks for the Michigan one.  In a upcoming post I expect to show the egg appendage of the Michigan one which may help in its speedy development.

Joseph G. Engemann      June 1, 2014

EVOLUTION INSIGHTS AUTHOR

The first missing picture intended to be posted with the first post on May 9 of last year (2013) is the picture below.

It was taken in 1957 in Colombo, Ceylon (now Sri Lanka) as I was returning from Australia.  The "snake charmer" said its fangs had been pulled so I wasn't too concerned about being bitten.  But back on the bus the driver said a lady had died from a bite from one a month earlier.  Then I remembered my herpetology professor, during work on my Master's degree at Michigan State University had told us about the fangs of snakes being replaced by others in waiting.

The anecdote may make you realize I shouldn't be taken too seriously, as I am, like most of us, prone to make mistakes and/or forget things.  Now, with my white hair and wrinkles, it doesn't bother me too much.

With all the "selfies" people are posting on their accounts, I thought maybe I would include one from about a year before the first one above.  It was in my lab in Hobart at the University of Tasmania with the Derwent River Estuary in the background.  I didn't need a fellow tourist to take it, I just used a self-timer with the camera.

It is not important to you, but I went through public schools in Ionia County, Michigan, before getting a B.A. at Aquinas College in Grand Rapids, Michigan; my major was Biology, my minor was English.  When I graduated in 1950 the Korean Was was soon to begin.  I delayed job hunting until a pre-induction physical would find me ineligible for service.  But they were desperate for bodies and I was fortunate to be sent to Germany, instead of Korea, following training at Camp Pickett in Virginia.  The year in Germany was accompanied by passes and leaves in which I visited about a dozen countries.  Many of my friends from basic training were sent as replacements to units in Korea.  The only one who contacted me after the war told me he and another buddy were wounded and another he heard of was killed.

The picture above is another self-timer one taken on maneuvers in Eastern Bavaria near the Czechoslovakian border.  It shows the tents of Clearing Company, part of the 118th Medical Battalion (the approximate equivalent of a MASH unit) of the 43rd Army Infantry Division.  I was discharged later that year (1952), too late to begin graduate school, got a job in a tool and die shop and liked the work so much I delayed return to school for over a year.

Most posts to follow this one will focus on the new points of evolution that I am trying to make understandable.  Previous posts lacked needed illustrations; and a few were too technical in hopes my colleagues would make the needed connections of how to correct current misunderstandings of evolution.

Joseph G. Engemann       May 31, 2014

LIVING FOSSILS

ANCIENT INVERTEBRATES?

Darwin, in his Voyage of the Beagle, laid out the theory about the formation of coral reefs, and atolls in particular, forming and only growing in shallow, warm, oceans but growing upward as land subsided or oceans rose.  His theory has largely been confirmed by evidence from boring deeply into Bikini and some other Pacific ocean coral islands.  Over a thousand feet of coral rock could be found in some locations.

I expected the growth represented generation after generation growing on top of the previous generation.  I thought some would get quite old by growing upward for a while, but I was surprised by the coral shown in the accompanying photo taken recently in the children's room of the Kalamazoo Public Library.

The photo shows skeletal part of a brain coral that appears to be growing from the middle of a similar coral underneath it.  I was  told it was donated by a local resident years ago after it had been collected in the Florida Keys region.

Below is a photo of a brain coral on the reef of Heron Island near the Southern end of the Great Barrier Reef.  The green wavy line next to it is the exposed mantle of a giant clam.

Corals and sponges are examples of invertebrates that could continuously grow upward as a reef sinks so that essentially the same organism remains near the surface for a very long time.  The first part and the last part would have the same genetic makeup, baring mutation, but would it still be the same individual.  It becomes a semantic problem to make a distinction.

So, what's the point?

The preceding is just an example of how organisms may almost suspend evolution.  As a result the long time between sexual generations means little chance for change as compared to most animals we know.  The one I have blogged about the most, the pogonophorans, happened to be the connecting ancestral group linking vertebrates to the protostomes.

Joseph G. Engemann        May 30, 2014

FINDING GOD

STARING AT THE WALLPAPER

The kitchen of our second house had a busy wallpaper.  If memories of it forty years ago are correct, it had a yellowish background liberally adorned with smallish nondescript flowers and foliage.  But colors of pale flowers were predominate and smaller contrasting splotches of red and a few other colors were scattered in no obvious pattern.

Staring at the widely spaced red marks it soon became apparent that they were in a geometric arrangement, perhaps a foot apart, of vertical, horizontal and diagonal rows.  After a few months of repeating the observation, probably accompanied by coffee and cookie treats, I made what to me was a remarkable discovery.

In my amazement at how the red stood out, although it was the most vividly colored mark, I may have wondered if I could find other colors in the same pattern.  Because when I looked for blue, and subsequently green and other, color patterns, the red pattern disappeared.  Each color became my focus, however I desired, and became easy to see and all, not surprisingly, conformed to the patterns previously noted for the reds.

CONSCIOUS SEARCHES

The mind is a remarkable thing.  You don't have to do much other than think about what you want to find and you often soon find it if it is there.  If I have a word in mind I can often find it quickly on a page, a list, or a jumble.  Scanning lists of people's names, in alumni publications or other listings, can be done quite rapidly to find those you know without even thinking or looking for their particular name.

If the world is our wallpaper we can enjoy a trip through endless landscapes more enjoyably if we, like Darwin, learn to observe the rock formations, hills, streams, plants, and animals while looking for or noticing relationships of one to the others.

Searching people, friends and others, we can usually find what we are looking for in them, either good or bad.  A bad experience with them early tends to make us notice the bad.  Likewise, a good first experience tends to make us notice the good later.  The repetition can confirm the original view because we may have become blind to the other view.

FINDING GOD

God is not hiding.  Old Testament writers found him in a gentle breeze or a burning bush.  In the New Testament he variously appears as a dove, tongues of fire, and as Jesus Christ.  To us, God can be seen in his works, not as blotches on the wallpaper, but in everything good that he created.  For us, the challenge is to program our search engine to look for the good in everyone.  You can also look for one, eternal, all-powerful God's works at night when the light from the sun, reflected off the moon, took only a few minutes to reach us; the light from the nearest star, a year or so to reach us; and light from the farthest stars, uncountable years to reach us.

Alternatively, follow your conscience and as you become aware of the things God does for you, you will find God in your own experiences more convincing evidence than you could get from me telling you of my experiences.

Joseph G. Engemann      May 17, 2014

HELLO WORLD

Why "Hello World"

I just checked my blog settings and found I have been blogging about a year to myself.  Some brave souls managed to find it, especially in the last few months after a daughter started to comment on a few posts to friends on Facebook or Twitter.

The settings were so private that it was not listed on blogger and search engines could not see it.

What have you missed?

If your interest is evolution

- the post of May 31, 2013 has the basics of a major boo-boo made a few years earlier and perpetuated in errors supposedly showing the evolutionary relationships of animal phyla.

- read the blogs about annelids, the pogonophora, and why the annelid theory of chordate origin should be reinstated.  Perhaps start with post number four, 05/19/2013, on how cognitive dissonance entered in to my finding out why that is so.

- an efficient line of early evolution leading from protozoans to flatworms can be found in last July's posts.

If you are interested in the creation/evolution debate [in addition to the post of 07/10/15 just added]

- posts of 06/12/2013 and perhaps 03/12/2014 might be helpful.

- other posts may also help you see I think the debate is meaningless; God created the living world by a process we recognize as evolution.

Quirky and not so quirky views about God, Evolution, Creativity, Science, and other items are scattered through the posts.  They still do not have graphic illustrations.  Perhaps that deficiency will be taken care of sooner rather than later.

Joseph G. Engemann    May 12, 2014

HORMONES BEFORE NERVES?

HORMONES TO NERVES?

Today, both interact in regulating functions of cells and organs, but which came first?

In many cases they interact to accomplish their job.  The same thing was probably true during the evolution that brought them to the way they work.  Hormones by definition operate on cells beyond the cells where they are produced.  But so do nerve cells.  The distinction is that hormones are chemical substances produced by cells but are transported to targets by the general circulation of the blood, with an exception for certain pituitary hormones noted below; neurosecretions are produced in nerve cells and transported along the axon to close proximity to the target cell.

HORMONES

Two methods are known by which hormones operate. 

In both methods the hormone is delivered to the target cell by the circulatory system and diffusion to the cell surface.  Peptide type hormones typically do not enter the cell.  They bind to a receptor that extends through the outer cell membrane and cause the inner side of the receptor to function as an enzyme that converts adenosine triphosphate (ATP) into cyclic adenosine monophosphate (cAMP).  The cAMP then activates the cell to do the function development had programmed it to do; thus the same hormone can perform different functions if particular cells with the receptors have different functions.

Steroid hormones typically have a different method of functioning.  They pass into the cell and attach to specific locations on a chromosome’s DNA.  The gene at that site is activated to produce the RNA that leaves the nucleus to interact in producing the product the gene specified.

NERVE CELLS

Nerves cells can control action of cells remote from the nerve cell body.  A long process, the axon, extends from the cell body to the target cell.  Proper stimulation of the cell body causes a transient depolarization of the membrane of the axon to rapidly progress to a termination closely applied to the target cell where neurotransmitters are released at the gap to activate the target.

The neurotransmitter can be ATP or some other molecule depending on the location and function of the cells.  In a few instances actual hormones can be released into the blood and be delivered by a special blood vessel network to a portion of the pituitary as part of the complex hormonal control complementing neuronal control of pituitary and its responsibility of secreting a variety of hormones controlling many other body systems.

EVOLUTION

The Final Step

Hormones generally have longer term, slower developing effects.  Nerves typically have a rapid response.  Sensory nerves and motor nerves enervating muscles have the fastest transmission. The response produced rapidly ceases because an enzyme in the gap between nerve ending and target cell contains an enzyme that rapidly degrades the chemical transmitting the stimulus. Nerves with less voluntary control transmit slowly to organs for less instantaneous responses.

An Intermediate Step

Some sponges have cells with short processes containing inclusions which have staining properties similar to neurosecretions.  Sponges do not have any rapid responses.  Some slow changes in the large opening, where water passing through the sponge leaves, have been reported.  Perhaps the closing is beneficial to the sponge during disruptive events when debris is settling into the sponge’s cavity.  A mechanism to send the distress signal from cells at the bottom of the cavity to cells around the opening could have selective value for survival if cells responded appropriately.  Elongated cells that had improved ability to deliver the message quicker would have suitable variations progressively selected until many generations and many new species later both hormones and nerves would provide the coordination we see today.

The First Step

It seemed to me that the one-celled animals (protozoans) might have chemicals analogous to hormones that control a portion of the cell but are produced within the cell.  The DNA does something like that via the RNA it produces.  But can the DNA be controlled?

The Experiment

Thirty-plus years ago I suggested a related study for a student looking for a research project.  During my master’s thesis topic, 60 years ago, I investigated some aspects of lipid chemistry in a protozoan, Tetrahymena.  I had used a technique others had described for synchronizing the divisions of Tetrahymena cells in their growth phase.  Heat shocks prevented completion of the division phase of the nucleus so the whole population was stalled at the same division stage.  Following return to normal temperatures most divided in synchrony about a half-hour later.

By ultra-sonically disrupting cultures during post shock periods and treating cultures that were not shocked with the disrupted cultures we hoped to find an induced peak of divisions within a half-hour.  There was no certain peak, although a few dividing cells in one culture was inconclusive evidence that was never followed up with more precise focus.  So the first protozoan “hormone” is yet to be discovered.

PHEROMONES

Chemical substances released by one animal in minute quantities that produce some specific behavioral response in others of the species are called pheromones.  A rock thrown to get your attention is not considered to be a pheromone.  Sex attractants are among the most widely studied pheromones.  Alluring perfumes are not pheromones either.  But some synthetic insect pheromones have been used to attract pest insects to traps.  Their release from many points in an infested field has also been shown to disrupt the male’s search for a female and make it less likely for reproduction to be successful.

The sex attractant pheromones of a closely related group of species from one insect family were found to consist of variations of the percentage of the same two or three volatile chemicals uniquely characteristic for each species.  That suggests one way new species could arise without geographic isolation.  Once success in reproduction correlated with a variant concentration, a new strain could evolve in its own particular direction.

Among other pheromones are alarm pheromones.  Trail marking substances could be used by the ant that placed them, and/or by others of the species.  Human pheromones are not well studied.  Two reasons may be significant.  Our ability to smell is worse than that of many other animals.  And the other is our reluctance to interfere during the private moments of others.  Could some of our intuitive decisions about others be based on otherwise unperceived pheromones?  Does a baby’s smell aide bonding or otherwise affect the mother?  Or vice versa?  Lots of possible pheromone responses may yet be found.

Joseph G. Engemann         May 10, 2014

PSYCHOANALYSIS OF A BLOGGER

Whither this blog?

I’ve sketchily covered the things that were most important to do

1.  Convince scientists that it is OK, right, and proper that God is the ultimate cause.

2.  Show them that the annelids and pogonophorans are a very significant connection in the tree of life.

3.  Show them that the deep sea environment and bombardment from space had a role in selecting pogonophorans for extreme longevity (hundreds of thousands of years) and that explains the genetic link this group shows in the tree of life with very diverse younger groups, as well as the error responsible for their contrary findings.

4.  Convince creationists that the proper evidence for the method God used in creation of life was the natural selection that scientists accept, and that even the chance aspects of it reflect the will and awesome creative power of God.

5.  Do all the above by leaving a written and/or electronic (this blog?) record.

I’ve often thought I could not accomplish this during my life due to the inertia of science and the tendency of the status quo to be perpetuated.  Why rock the boat?

Some of the things still to do

Of lesser importance are the many examples of aspects of evolution that I have encountered, not only some of them on my own, but many suggested by others, and some accepted and well known by specialists.

1.   Details of the evolutionary events leading to our left brain, right brain dichotomy in function and thinking.

2.  The probable evolutionary pathway from protozoans to sponges to cnidarians to flatworms and the consequent origin and fate of nematocysts and rhabdites.

3.  The related evolution and connection of the endocrine and nervous systems, probably my next post.

Some self psychoanalytic aspects

As I’ve learned to respect myself, I’ve learned to respect others (at least I should) as having equal love from and access to God.  My inadequacies were part of my development essential to pursuing an erratic path to an unusual knowledge of evolution (that still is filled with knowledge gaps).

Even at 85 years of age and questionable health the mind is still working.  There were gaps of years along the way where it seemed nothing was happening upstairs.  But this morning while showering a new insight on early evolution of the first few animal phyla was developed.  Before I forget I’ll make a note here [It involves the fusilinids, that were enormous foraminiferan protozoans, whose calcareous skeletal parts may have been lost from early sediments due to anoxia and consequent acidification causing them to dissolve, their coexistence and interaction with sponges  and possible role of somewhat related events in hormone/nervous system origin].

Failure can be a breeding ground for success.

We can learn from almost everyone and almost everything.

Write it down, your memory is not as great as you think it is.

In all likelihood, today is neither the best, nor the worst, day in your life.  So enjoy it, it is what you have.

In answer to the first question, whither this blog, I now hope to go on to more interesting aspects of evolution related topics, after accessing the previous four blogs as being  progressively more boring.  OK, so maybe it won’t all be on evolution.  After all, I've gotten used to my family’s and friend’s eyes glazing over when I bring up the topic – evolution.

Joseph G. Engemann        May 3, 2014