Sentences with phrase «animal phyla»
The phrase "animal phyla" refers to different groups or categories in which animals are classified based on their shared characteristics or traits. Full definition
It centers on one of the most remarkable events in that history, the relatively rapid emergence of animal phyla in the Cambrian.
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According to Strausfeld, confirmation of this shared ground pattern in the vertebrate hippocampus would suggest that it originated from a very ancient common ancestor likely to have lived about 600 million years ago just before the Cambrian explosion, a relatively short period when most major animal phyla emerged.
Meyer holds that the emergence of animal phyla in the Cambrian demonstrates the existence of an intelligent designer.
«Animal evolution: Sponges really are oldest animal phylum.»
The initial phases of animal evolution proceeded faster than hitherto supposed: New analyses suggest that the first animal phyla emerged in rapid succession — prior to the global Ice Age that set in around 700 million years ago.
It had been assumed that such lateral gene transfers were uncommon, but their existence in arthropods, the largest animal phylum, suggests that such transfers may be a significant evolutionary mechanism.
The fossil record suggests complex multicellular life emerged about 600 million years ago in a relatively short period termed the «Cambrian explosion,» during which most major animal phyla appeared.
The answer to the question of whether the sponges or the comb jellies (also known as sea gooseberries) represent the oldest extant animal phylum is of crucial importance to our understanding of organismic evolution.
There have been several thousand magnetic reversals since the evolution of animal phyla about 600 million years ago, so any creatures that experience seriously detrimental effects when a flip occurs have probably been removed by natural selection.
In subsequent studies the researchers plan to analyze further relevant datasets in order to test different scenarios of the evolution of the earliest animal phyla.
These are two of the most abundant animal phyla.
al. (1999) for example, recently conducted phylogenetic studies divergences among animal phyla, plants, animals and fungi.
Finally, they conjecture that the basal animal phyla (Porifera, Cnidaria, Ctenophora) diverged between about 1200 and 1500 million years ago.
Also see: Subkingdom Eumetazoa Kingdom Animalia Kingdom Plantae Animal Phyla Theory of Endosymbiosis
Such ancient core reproductive components should fulfill the following criteria: present in most, if not all, of the major lineages of animals undergoing sexual reproduction; originated around the time when gametogenesis likely evolved; demonstrated conservation at the sequence, expression and functional levels in species from diverse animal phyla.
One such mystery is why animal phyla (groups of animals that share an evolutionary history) differ dramatically in the diversity of species they contain.
Hodda (2011) estimates that parasitic nematodes exist in every other animal phylum larger than themselves, and all plants, with the exception of some marine plants.
A new study by an team of Ludwig - Maximilians - Universitaet (LMU) in Munich reaffirms that sponges are the oldest animal phylum — and restores the classical view of early animal evolution, which recent molecular analyses had challenged.
Collectively, these fossils were termed «weird wonders» by the evolutionary biologist Stephen Jay Gould; they possess some, but not all, of the characteristics shared by their modern relatives, and so are crucial for understanding the early evolution of animal phyla.
Many of the animals phyla that are losers in terms of present - day species numbers tend to be in the ocean, and because of human activity, they may go completely extinct.»
Evidence for comb jellies as the earliest branching animal lineage first emerged in 2008, a decade ago, in the first, large - scale, phylogenomic analysis of the animal phyla.
The fossil record reveals that almost all of the animal phyla known today had come into existence by the beginning of the Cambrian Period some 540 million years ago.
After the sponges and cnidarians came the worms — the first creatures with bilateral symmetry, after which came an «explosion,» as Sogin calls it, of big - animal phyla.
His case against current scientific explanations of the relatively rapid appearance of the animal phyla rests on the claim that the origin of new animal body plans requires vast amounts of novel genetic information coupled with the unsubstantiated assertion that this new genetic information must include many new protein folds.
Except for the Ediacaran biota, most animal phyla (some that persist and some that did not) appear in the fossil record rapidy and essentially simultaneously at the base of the Cambrian period, some 570 million years ago, an event known as the Cambrian Explosion.
Trained as an experimental embryologist, Martindale has worked on various aspects of the development and regeneration of some 14 animal phyla.
Chemosynthetic symbioses evolved independently multiple times in at least nine animal phyla and from at least 12 lineages of free - living bacteria.