Evolution of Tigers
Introduction To the Modern Tiger
Evidence of Evolution
Paleontology-the science of the forms of life existing in previous geologic periods, as shown by their fossils example:finding a fossil
Coevolution-the evolution of 2 or more interdependent species, one adapting to changes in the other example: the exsistence of mitochondria in a eukaryotic cell
Pseudogenes-DNA sequences that resemble functional genes but are believed to have no purpose example: the genes that do not code for proteins
Speciation-the formation of new species as a result of geographic, physiological, anatomical, or behavioral factors that prevent previously interbreeding populations from breeding with each other examples: natural selection, sexual selection, and migration
Prezygotic Isolation- solitude before fertilization example: geographic isolation
Postzygotic Isolation- creation of solitude arfter fertilization
Postzygotic Isolation-creation of solitude after fertilization. example: embryological arrest
Adaptive Radiation-the diversification of an ancestral group of organisms into a variety of related forms specialized to fit different environments or ways of life, each often further diversifying into more specialized types example: the Hawaiian silversword `ohana
Stasis-the state of equilibrium or inactivity caused by opposing equal forces. example: two people pushing on a door from opposite sides
Gradualism-a tenet in evolutionary theory maintaining that species evolve slowly and continuously over long periods of geological time. example: the length of time it took humans to evolve
Puntuated equilibrium- the evolution of species proceeds in a characteristic pattern of relative stability for long periods of time interspersed with much shorter periods during which many species become extinct and new species emerge
example: natural selection acts and humans get taller
Means of Evolution
The means in which tigers evolved were coevolution because they evolved based on their prey. The teeth shrank and the tail grew because of the prey.
Rate of Evolution
The rate of evolution of tigers is gradualism, because they evolved gradually overtime, over many generations.
By: Julia Everitt
Tigers are in the kingdom Animalia and their species name is Tigris. The scientific name for tigers is
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There is evidence of evolution of tigers over time. Pictured below is the fossil of a head of a saber toothed tiger, an ancestor of the modern tiger. Though tiger is in the name, the saber-toothed tiger is not related all that closely to tigers. Though they may not be closely related they still provide evidence of evolution in tigers. The most obvious difference between saber-toothed tigers and modern tigers is the teeth. Though this may be the most obvious difference it is not the only difference. Another difference between modern tigers and the saber-toothed tigers shown in fossils is the tail. The saber-tooth had a short, bobtail where the modern tiger has a longer
tail. The short tail suggests that the saber-tooths didn't chase their pray. Another thing shown by fossils is that bones had recovered from serious injuries which would have required the help of other saber-tooths, suggesting they hunted in packs unlike today's tigers who hunt alone.
Another thing that provides evidence of evolution is homologies. DNA testing was done on South China tigers and it is believed that they are the species all other subspecies of tigers evolved from. The DNA testing also showed homologies with very early fossils (2 million years) of tigers that are much smaller than those of today.