Evidence of Evolution
Hello, today we will be covering the interesting evidence on how we can trace evolution!
There is much evidence that supports the theory of evolution. Primary sources of evidence include the fossil record, comparative morphology, and biogeography.
Fossil Records are remains/traces of past organisms. This record provides valuable insight into determining change over a period of time.
These fossils can be dated by examining the rate of carbon 14 decay and the age of where fossils are found. This provides geologists data for the organisms found.
Comparative Morphology is the analysis of the structures of living and extinct organisms. Homology refers to characteristics in related species that have similarities despite differing functions.
This can be classified into three types, embryonic, vestigal, and molecular homology.
Embryonic homology is when many species have similar embryonic development
Vestigial structures are structures conserved despite no longer being useful
Molecular is where species share similar DNA and amino acid sequences
Homologous structures are characteristics that are similar between two species due to a common ancestor. An example of this are arm bones of many species.
Convergent evolution is where similar adaptations have evolved in distantly related organisms due to similarities in environments.
Analogous structures are similar but differentiated through the origins of their evolutions.
Structural evidence provides evidence for common ancestry of all eukaryotes. These fundamental and cellular features/processes are conserved across organisms.
Cellular examples include:
Membrane-bound organelles
Linear chromosomes
Introns within genes
Biogeography describes the distribution of animals and plants geographically
Species on oceanic islands resembling mainland species
Species on the same continent being similar, and distinct from species on other continents