Unit 2: Biodiversity Flashcards
DNA Evidence
Comparing DNA and amino acid sequences helps scientists see how closely related species are.
What does DNA tell us?
Similar DNA sequences between different species suggest a common ancestor.
What are fossils?
Preserved remains or traces of organisms from the past
Where are fossils found?
They are found in sedimentary rock layers
What do fossils show?
How species have changed over time
What do fossil records provide?
They provide chronological patterns of change, showing transitions between ancient species and modern ones.
What is Biogeography?
The study of where organisms live and how they got there
What do patterns of distribution show?
Patterns of distribution show that species evolved differently in different environments.
What do isolated environments have?
Isolated environments have unique species that evolved separately but show similarities to mainland species.
What is common ancestry influenced by?
Common ancestry is influenced by geographical separation.
What is embryology?
It is the study of how organisms develop before birth.
Do early embryos of different species look similar?
Early embryos of different species look very similar, showing common structures.
What do early embryos suggest?
The similarities within early embryos suggest that these species share a common ancestor.
Homologous structures
Body parts that are similar in different species because they were inherited from a common ancestor.
Example of a homologous structure
The bones in a human arm, a bat wing, and a whale flipper have different functions but similar structures, showing common ancestry.
Why are homologous structures important?
They show how species have adapted structures for different uses over time while retaining a shared origin.
Analogous structures
Body parts that perform similar functions in different species but are not inherited from a common ancestor.
Example of an analogous structure
Wings of birds and insects.
Why are analogous structures important?
Shows convergent evolution, where species evolve similar traits independently to adapt to similar environments.
Vestigial structures
Body parts that have lost their original function through evolution
Example of a vestigial structure
Human appendix, whale pelvic bone
Why are vestigial structures important?
Evidence of changes over time and adaptation to new environments.
Adaptive radiation
The rapid evolution of many new species that possess adaptations that allow them to fill previously empty ecological roles, or niches
A species evolves quickly to allow themselves to better the environment.
Speciation
The formation of a new and unique species over the course of evolution
Microevolution
Small-scale changes within a species (e.g., changes in gene frequency).
When can microevolution be observed?
Microevolution can be observed over a short period, like the development of antibiotic resistance in bacteria.
Macroevolution
Large-scale changes that occur over long periods and result in the formation of new species or major changes in body plans.
What does macroevolution include?
the evolution of mammals from reptiles
What type of life does microevolution involve?
Specific species
What type of life does macroevolution involve?
All life
