Lesson 4: Evidence of Evolution & Common Ancestry

Morphological evidence

refers to structural characteristics observed in the anatomy of organisms, which can indicate evolutionary relationships and common ancestry.

• evolution is supported by scientific evidence from many disciplines

Half-Life problems

involve calculating the time required for half of a radioactive substance to decay, demonstrating principles of radioactive dating and decay rates in understanding geological and biological timelines.

Morphological Similarities

are structural traits shared by different species that suggest a common ancestry and evolutionary relationships among them.

Homologous structures

are anatomical features in different species that are similar due to shared ancestry, although they may serve different functions.

eg. forelimbs of mammals like humans, whales, and bats.

Embryonic Similarities

refer to the similarities in the early developmental stages of different species, indicating a shared evolutionary origin despite eventual differences in form and function.

Vestigial Structures

are remnants of organs or structures that had a function in an early ancestor but are reduced or nonfunctional in modern descendants, providing evidence for evolutionary change.

Analogous Structures

are anatomical features in different species that serve similar functions but do not share a common evolutionary origin, often resulting from convergent evolution.

• CONNECTED TO CONVERGENT EVOLUTION eg. include the wings of birds and insects, which have evolved independently to facilitate flight.

Biochemical Evidence

refers to the molecular similarities in DNA, proteins, and metabolic pathways between different species, supporting the idea of common ancestry and evolutionary relationships.

• the greater the amino acid difference the more time has passed since their divergence and can indicate how closely related species are in an evolutionary context.

Phylogenic Tree

is a diagram that represents evolutionary relationships among various biological species or entities based on similarities and differences in their genetic or physical traits.

• the more distantly related species are, while further right indicates closer relationships, illustrating the concept of common descent.

Biogeography

is the study of the geographic distribution of species and ecosystems, and it provides insights into how geographical barriers and environmental factors influence evolutionary processes and the distribution of organisms.

• can be caused by endemic species in islands close to mainland, which are species that are not found anywhere else on the planet

• Contiental drift