Evidence for Change Across Time

Physical Anthropology
Developmental Biology
Evolutionary Biology
Physical Anthropologists are scientists who study how
humans and their ancestors have changed biologically
over time.
Similarities in skull structure offers evidence of
common ancestry.
Changes in skull structure indicate change
across time.
The study of prehistoric life and evolutionary
relationships through the fossil record.
Evidence for Change through the fossil record
Evidence for change across time
Fossil record shows gradual change over time of a
large number of species
Higher Rock levels
 Younger Fossils found here.
 Fossils are similar to modern
Lower Rock levels
 Older fossils found
 Fossils are much different
from modern species
Scientists who study the stages of growth and
development that living organisms pass
through as they grow from fertilized egg to
mature adult.
Embryology- Branch of developmental biology
that focuses on the early development of
organisms before they are born or hatched.
Embryo- Developing organisms during the
prebirth/prehatch stage.
The presence of DNA in ALL living organisms
is evidence that all living things evolved from a
common ancestor.
Percentage of DNA that is the same as
human DNA
Fruit Fly
Domestic cat
Monkey (an old world primate)
Gibbon (a lesser ape)
Chimpanzee (a great ape)
The Bonobo’s and Chimpanzee’s DNA sequencing is
98% the same as Human DNA sequencing.
This is strong evidence that humans, chimpanzees and
Bonobos share a common ancestor.
Evolutionary Biologists are scientists who study
how living organisms change physically over
Charles Darwin wrote “The
Origin of Species”
Evolution through Natural
Homologous Structures- Characteristics that
are similar among different organisms because
they evolved from a common ancestor.
Vestigial Structures- Structures that seemingly
serve no purpose in some animals that are
functional in other animals.
•Evidence for common ancestor
•Structures evolved and changed across
Shows Evidence of change over time as
structures that no longer serve a purpose are
still present.
The Pelvic Girdle
was functional in
the ancestors of the
modern Whale.
The structure no
longer serves a
purpose but is still