Nested Hierarchy:
Groups of related organisms share suites of
similar characteristics and the number of shared
traits increases with relatedness.
The higher order category must be suitable for
the lower order sublev
...
Nested Hierarchy:
Groups of related organisms share suites of
similar characteristics and the number of shared
traits increases with relatedness.
The higher order category must be suitable for
the lower order sublevels.
Ex. Ecosystem refers to both physical
environment and population of organisms.
Ex. 1 Ex. 2
Evolution:
What Is it?
genetic change
change in the allele frequencies of a
population
not necessarily good or bad
Why Study it?
To manage exploitation
*we eat the big fish out of the population,
that’s artificial/human selection
To understand mutating bacteria (antibiotic
resistance)
Unionid Larvae Mussels:
Life Cycle:
1. Fertilization
2. Larva (Glochidia)
3. Fish Host
4. Juvenile
5. Adult
Glochidia Larvae:
Cannot swim or crawl
Released by mussel, gets into fish gills
(host), evolutionary characteristic
Attach to host
Unionid Strategy #1: Bait
Conglutinates:
The membrane in which the Glochidia are
enclosed.
Method of infecting fish host
The conglutinate membrane resembles fish
prey (lure), trick the fish.
On a line attached to the mussel.
Glochidia released from conglutinate
membrane when fish approaches.
Unionid Strategy #2: Host Capture
Mussel grips host and pumps Glochidia in
Simple Lure:
Modified mantle tissue catch fish attention
Complex Lure:
Mantle tissue mimics fish (host) prey
Advantages and Disadvantages of Lure
Complexity?
Advantages Disadvantages
Enables attraction of
needed host fish for
reproduction
(obligate parasitism)
more complex the
more specialized the
host fish
Mussels utilize more
energy to develop
complex lures
(conglutinates) to
attract needed host
fish.
Developmental Perspective:
Different lure complexity, not necessarily “less
evolved”, just not trying to attract the same host
fish, or can reproduce with a larger variety of
host fish, …requires less complexity.
Ecological Perspective:
Greater lure complexity dictates type of host
fish, mimicry of host fish’s prey to trick
pump Glochidia reproductive success
(obligate parasitism phase). As complexity
evolved, the more reproductively successful
mussels survived and passed their genes. (small
mutations over time).
Veliger Larvae Mussels:
Ex. Zebra Mussels
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