That’s inconvenient if one is arguing for common ancestry of vertebrates.
Embryology
Researchers: Contrary to a century-long assumption, we are more closely related to snails and flies than to starfish
If things are really uncertain at such a fundamental level (protostomes vs. deuterostomes), evolutionary biology could do with a lot less dogmatism in addressing the public.
Watching a salamander grow from a single cell
From National Geographic: “…van IJken was able to shrink what would take around four weeks in nature down to just six minutes…”
Not-yet-specialized cells seem to know where to go
Researchers: Tohoku University scientists have, for the first time, provided experimental evidence that cell stickiness helps them stay sorted within correct compartments during development. How tightly cells clump together, known as cell adhesion, appears to be enabled by a protein better known for its role in the immune system.
Recent paper: The problem of biological form remains unsolved
Linde-Medina: “Embryonic development, which inspired the first theories of biological form, was eventually excluded from the conceptual framework of the Modern Synthesis as irrelevant.” Shouldn’t that have been a wakeup call?
Eggbound baby gulls warn nestmates of threats
Well, if the embryos are shaping their development in response to warning cries, that puts a whole new spin on “evolution.”
Becoming: Design in action
Becoming from Aeon Video on Vimeo. Watch a single cell become a complete organism in six pulsing minutes of timelapse. A film by Jan van Ijken More about the life form portrayed.
Fish turn into fluids, which enables embryo development
And, it turns out, they must: Zebrafish aren’t just surrounded by liquid, but turn liquid – in part – during their development. As the zebrafish embryo develops from a ball of cells to a fully-formed fish, a region of the embryo switches its phase from viscous to liquid in a process known as fluidity transition. Read More…
Remarkable vid of a mouse embryo developing
This series of videos from McDole et al. shows the development of a mouse embryo, captured using adaptive light-sheet microscopy, and highlights cell division (part A), cell movements (part B) and tissue dynamics (parts C, D) during embryogenesis. Paper. McDole, K., Guignard, L., Amat, F., Berger, A., Malandain, G., Royer, L.A., Turaga, S.C., Branson, K., Read More…
At Oscillations: How we go from a sphere to a torus
At her blog, Oscillations, Suzan Mazur reports on the lecture series Simons Center for Geometry and Physics has been hosting at Stony Brook University, on Nonequilibrium Physics in Biology: Among the more interesting presenters is Kim Sneppen, a professor of complex systems and biophysics at Neils Bohr Institute in Copenhagen, who addresses the diversity of Read More…
Mechanics as well as genetics is needed for viable embryo development
From Suzan Mazur at Oscillations, With the ramping up of investigations in various parts of the world into the mechanics of biology, I’ve decided to post my conversation with Institut Curie biophysicist Emmanuel Farge on the role of mechanics in reprogramming the embryo [2010], relating to his work first published in the scientific literature in 2003, Read More…
Cells are chock full of information systems, not just DNA
From Jonathan Wells at ENST, looking at a variety of systems, including the bioelectric code: Regional differences in cells and embryos can be specified in other ways besides localization of RNAs in the cortex. Two of those ways have been studied in great detail: the “sugar code” and the “bioelectric code.” Most proteins in living Read More…
Biophysics is starting to matter in evolution
From Suzan Mazur at Oscillations: The mechanics of morphogenesis is something European scientists, in particular, seem to find intriguing. However, physical biology is an approach many classical biologists in America have had a difficult time in the past understanding as well as accepting, as evidenced by vociferous attacks in the blogosphere on scientists working in Read More…
The “developmental hourglass” doesn’t actually need to be true
It’s too cool a concept for accuracy to matter. Further to “Remember the ‘developmental hourglass’? Well, not so fast,” Jonathan Wells writes to point out that vertebrate embryos more closely resemble each on another than do their adult forms only if one carefully cherry-picks the desired stages, which are long after the beginning of development. In Read More…
Remember the “developmental hourglass”? Well, not so fast.
“The hourglass model of embryonic evolution predicts an hourglass-like divergence during animal embryogenesis – with embryos being more divergent at the earliest and latest stages but conserved during a mid-embryonic (phylotypic) period that serves as a source of the basic body plan for animals within a phylum.” Well, not so fast: From Hajk-Georg Drost, Philipp Read More…