Evolution Of Prokaryotes

Decent Essays
Evolution, the process by which populations have changed and modified over generations, is the key to explaining the phenomenon that allowed single celled prokaryotes to be the ancestors to all life on earth. The first life on earth was believed to be prokaryotic cells, which lacked a nucleus to encase their DNA, while animals are multicellular, heterotrophic, eukaryotes, whose DNA and other organelles are encased. Somehow, the populations of prokaryotes on the early earth became more complex organisms such as animals over the generations, through evolution. To begin to comprehend this process, one must first look at how cells evolved from prokaryotes into the eukaryotes that make up the animal body.
Prokaryotes originated over 3.5 billion
…show more content…
There is no denying that the influence of mutation, natural selection, migration, drift, and outside forces have shaped the drastically diverse group of animals that are around in the present. Wherever there is diversity within populations, nature works on these variations, favoring organisms with the best adaptations, and if the evolution of humans has anything to say, those with the most complex structure. The separation of populations has led to even more diversity, creating new species by isolating groups from each other, and so forth. A brief summary of how they’ve evolved, animals came from a protist ancestor, who evolved over time into two groups, those with tissues, and those with no true tissues, parazoa (sponges). Animals with tissue can be divided further between those who evolved with radial symmetry and are less active (radiata) compared to those who evolved with bilateral symmetry, who are more physically active (bilateria). The bilateria can be divided between animals with body cavities and those that lack them (acoelomates) and those whose body cavities aren’t completely lined (psuedo- coelomates). Some of the bilateria have segmented body parts, and all of them are either protostomes (whose first opening is the mouth) or deuterostomes (whose first opening is the anus). As animals evolve, they arguably become more complex and have a tendency toward bilateral symmetry, active searching for food, and cephalization, where the bulk of their nervous tissue is centered at the front or head, and an overall evolution toward intelligence. To explain animal evolution completely would be a difficult task, but understanding general patterns and how life got from single celled prokaryotes to multicellular, complex organisms is a good way to begin the
Get Access