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Printable Handouts
Navigable Slide Index
- Introduction
- Main message
- Example 1 - mobile phone evolution
- Example 2 - metazoan animal evolution
- Model systems go from tractable to complex
- Introducing the placozoan Trichoplax
- Metazoan - definition
- Talk outline
- Biology of placozoa - morphology
- Historic bookmarks
- The marginal cells
- New microscopic substructures of placozoa
- Biology of placozoa - reproduction
- Bisexual reproduction - poorly understood
- Biology of placozoa - ecology
- Searching for placozoa (1)
- Searching for placozoa (2)
- Global placozoans show ecological separation
- Biology of placozoa - genetics
- Closest related placozoan lineages - high identity
- Trichoplax adhaerens - Grell clone
- Biology of placozoa - physiology
- Endosymbiontic bacteria - important for adaptation
- Staining placozoans with cell-cycle markers
- Placozoans show self/non-self tissue recognition
- Placozoans have vision
- TriPax-B may affect the phototactic behavior
- Comparing placozoa to other metazoa
- Hox genes
- Comparison of mitochondrial genome sizes
- All major gene families are present
- Gene families & receptors are less complex
- Parallel evolution - diploblasts & triploblasts
- Different opinions on parallel evolution hypothesis
- Different evolution schemes suggested
- Placozoa H25
- The new placula hypothesis
- Hox-like genes - candidates for saltational change
- 5 Hox-like genes expressed in eleutheria medusae
- Hox-like genes knock-downs affects phenoytpe
- Hox-like genes can fuel a bauplan change
- How could we derive symmetry?
- Cnox-3 marks the oral pole in hydrozoon eleutheria
- The new placula hypothesis demonstrated
- Summary
- Thank you
Topics Covered
- Trichoplax and the origin of animal complexity
- Complex patterns usually evolve from more basic patterns
- Introducing the placozoan Trichoplax
- Metazoan – definition
- The Biology of Placozoa
- Trichoplax adhaerens: Grell clone
- Comparing Placozoa with other Metazoa
- Parallel evolution: diploblasts & triploblasts
- The new Placula hypothesis
- Hox-like genes
Talk Citation
Schierwater, B. (2016, March 31). Trichoplax and the origin of animal complexity [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved December 3, 2024, from https://doi.org/10.69645/VVOS6507.Export Citation (RIS)
Publication History
Financial Disclosures
- Prof. Bernd Schierwater has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
Other Talks in the Series: Evolutionary Physiology
Transcript
Please wait while the transcript is being prepared...
0:00
My name is Bernd Schierwater.
And I'd like to introduce you to my
favorite animal, Trichoplax, today.
Trichoplax is a very
exciting animal, as I
will show you
during this lecture.
And the title of the lecture
is "Trichoplax and the Origin
of Animal Complexity."
0:19
Basically, I have only main message.
But this message is quite simple.
All I have to say is in evolution,
complex patterns usually
evolve from more basic patterns.
And of course, there
are other opinions.
But no matter what politicians
or religions tell us,
I think in the normal case,
we should stick with this method
that complexity evolves
from basic patterns.
0:47
So I have a simple example here.
And the example is
mobile phone evolution.
And I think we have good evidence
that mobile phone evolution went
from big and simple
to smaller, and even
smaller, and even more complex.
But the good proof is
easy to obtain simply
because mobile phone evolution
occurred within the lifetime
of a human being.
1:14
In evolution is a little
more complicated.
But the principle is the same just
that you don't have direct evidence,
we cannot observe
it in lifetime, while
we depend on indirect evidence.
But nonetheless, I make the claim
that even in animal evolution,
everything started with elementary
bauplans and very simple.
And from there,
we went from Trichoplax
all the way down there, for example,
through cnidarians to bilaterians.
And this is the point
I'm going to Illustrate.
Actually, I am going to enter
the lecture with an idea
how we can transform the little
Trichoplax down at the very bottom
into another bauplan much more
complex like the two shown here.