Evidence for Evolution There are 3 major pieces

Evidence for Evolution

There are 3 major pieces of evidence for evolution • I. Fossils • II. Embryos • III. DNA

I. Fossils • We can tell how old fossil using two methods indirect dating and directing dating. • Fossils show the form and structure of groups of organisms that have changed over time.

Indirect Dating • Older fossils deeper down, younger fossils up top

Direct. Method

Fossils show change over time

Fossils show homologous structures

Homologous Structures • Homo= same • Same/similar skeletal (bone) structure with the same or different function depending on their environment. • This is evidence that these species shared a common ancestor at one point.

Examples of Analogous Structures Although insect wings allow them to fly, they do not contain bones. *Insect wing and bird wings are analogous structures.

Analogous Structure • Think “An” = Another • *Another skeletal structure with the same function

• Vestigial structures are body parts that seemingly have no purpose or function. • They are proof that once we shared a common ancestor.

* What are vestigial structures evidence of?

II. Embryos • Similarities between different species of embryos show evidence they shared a common ancestor at one point in time.

DNA • Similarity in DNA sequences between different species also is evidence that certain species a more recent common ancestor.