(5) Evolution

Evolution

Evolution

the change in inherited traits over successive generations in populations of organisms. This allows organisms to adapt and survive in their environment

Fossil Records

are traces of organisms that lived in the past and were preserved by natural process or catastrophic events. It documents the existence of now-extinct species that are related to present-day species

Imprints

shallow external molds left by animals or plant tissues with little or no organic materials present

Compressions

are animals or plant tissues preserved in sedimentary rock and is framed with more organic material

Relative Dating

the age of rock is compared to the other rock layers

Radiometric or Radioactive Dating

methods used to determine the age of rocks using the decay of radioactive isotopes of carbon 14 which is present in rocks when the organism died

Comparative Anatomy

study of the similarities and differences in the structure of different species

Homologous Structures

It is related to Divergent evolution where specific species have common ancestors but they adapt different traits and functions.

Analogous Structures

It is related to Convergent evolution which means 2 or similar species evolve similar traits despite having different ancestors.

Vestigial Structures

body parts that are useless of leftover from a previous ancestor in which they were useful

Embryonic Development

the portion of the life cycle that begins just after fertilization. Many organisms have similar embryos, supporting the idea of common ancestors

Genetic Information

small mutations or changes in the DNA eventually lead to the evolution of new species

Catastrophism (Werner/Cuvier)

this states that the earth and geological events had formed suddenly as a result of some catastrophe.

Uniformitarianism (Hutton/Lyell)

tells us that the earth has always changed in uniform ways and that the present is the key to the past

Jean-Baptiste Lamarck

develops one of the first theories on how species changed. He concluded that organisms of higher complexity had evolved from pre-existing, less-complex organisms

Theory of Need

organisms change because they need to, for an organism to evolve a structure, it must need the structure

Theory of Use and Disuse

if you don't use it, you lose it. Organisms develop specialized characteristics by the use and disuse of organs

Theory of Acquired Characteristics

if a parent acquires body structure during its lifetime, it would pass on that characteristic structure to its offspring

Charles Darwin (1809-1882)

proposed an entirely different mechanism to account for the evolution of species. His theory of evolution by natural selection became the foundation of modern evolutionary studies.

Darwin's Finches

he was able to see 13 varieties of finches which varied in size and shape, from island to island. It took him 20 years to organize the data

The Origin of Species

the book that is written by Charles Darwin. In this book, he presented his theory of evolution based on natural selection

Natural Selection

individuals within a population with the most favorable traits for an environment survive and pass in those traits

Species Overproduction

organisms that tend to overproduce

Competition

there is a struggle of existence and the survival of the fittest. Living space and food are limited

Variation

No 2 individuals are the same. Plants and animals of the same species differ in size, strength, and adaptive structures

Adaptation

a process of becoming better suited to the environment and improve on organisms chance of survival

Natural Selection

environment selects organisms that survived to be the parents of the succeeding generations

Speciation

favorable adaptation gradually accumulate in the species and unfavorable ones disappear

Archaeopteryx

between reptile and birds

Eusthenopteron

amphibious fish

Seymouria

reptile-like amphibian

Mold

buried organism disappears and leaves an empty space

Cast

mold filled by minerals (replica of organism)

Petrification

minerals replace hard parts (bones, teeth, etc.) of organism

Amber

entire organism fossilized in tree sap

Frozen

entire organism frozen in ice

Trace

footprints, trails, etc.