Sirenian Evolution/Genomics
Sirenians closest living relatives, in the order Proboscidea.
What are elephants?
Genes involved in sensing vibrations and hearing help baleen whales in this key activity.
What is communication?
This could determine whether a female whale successfully reproduces in a certain year.
What are energy stores?
These complex river environments reduced opportunities for male display and contributed to the loss of tusks and a shift toward sperm competition.
What are labyrinthine river systems?
Genetic changes to the iodide transporter NIS helped sirenians adapt to a diet rich in this marine plant nutrient source.
What is seagrass?
During the Oligocene, dense patches of these tiny prey organisms developed, a key food source for mysticetes.
What are krill and phytoplankton?
This breeding pattern involves males mating with multiple females.
What is polygyny?
This is when many males escort one fertile female.
What is scramble promiscuity?
Modern manatees show extreme reduction of these limbs, documented step-by-step in their rich fossil record.
What are hindlimbs?
In order to engulf large volumes of water, mysticetes evolved bowed jaws and larger oral cavities to support these two specific types of filter feeding.
What are lunge feeding and skim feeding?
Male mysticetes may use these three strategies to successfully reproduce.
What are sperm competition, song, and competition with other males?
This species of sirenian is a seasonal breeder.
What is the breeding strategy of amazonian manatees?
The loss of the gene KCNK18 leaves modern sirenians vulnerable to climate change, because they struggle to sense and react to this environmental threat.
What are cold spells?
The ENAM, MMP20, and AMBN genes were once responsible for developing these structures before mysticetes began filter feeding.
What are teeth?
For many whales, they migrate towards this area to breed.
What is the equator?
In these species of sirenians, breeding is continuous and NOT seasonal.
What are Caribbean Manatees and Dugongs?
Along with Proboscidea and the extinct Desmostylia, sirenians belong to this ancient clade named for an ancient sea.
What is Tethytheria?
This gene helped baleen whales reach their large size by preventing cancer as a tumor suppressor.
What is TP53?
In these species of whales, females mate with more than one male in a breeding season.
What are Bowhead, Gray, and North Atlantic Right whales?
This is when males gather to perform competitive displays and courtship rituals to off their genes.
What is Lek mating/ Lekking?