What type of evolution do marsupial and placental mammals exhibit?
Convergent evolution produced a suite of marsupials that resembled contemporaneous placental mammals and included forms similar to large felids (in the family Thylacoleonidae).
Why are the marsupials mammals an example of convergent evolution?
These animals are an example of convergent evolution. Since then, they have evolved independently from each other, largely because marsupials have lived in geographical isolation from mammals for over 100 million years.
What is the parallel evolution between marsupial and placental mammals?
Parallel evolution implies that two or more lineages have changed in similar ways, so that the evolved descendants are as similar to each other as their ancestors were. The evolution of marsupials in Australia, for example, paralleled the evolution of placental mammals in other parts of the world.
What do marsupials have in common with placental mammals?
Both marsupial and placental mammal groups give birth to live young. Each animal in an ecosystem occupies a specific position.
How placental mammals and Australian marsupials show convergent evolution?
When species start different and then become more similar, this is known as convergent evolution. Convergent evolution can be seen in Australia’s marsupials and North America’s placental mammals. These two subclasses of mammals have adapted to a specific food source, locomotor ability, or environment in similar ways.
What is the difference between placental mammals and marsupials?
A marsupial is a mammal that raises its newborn offspring inside an external pouch at the front or underside of their bodies. In contrast, a placental is a mammal that completes embryo development inside the mother, nourished by an organ called the placenta.
How did placental mammals evolve?
Fossil evidence suggests they evolved after the end-Cretaceous mass extinction event about 65 million years ago that ended the age of dinosaurs; and the “explosive model” based off this data proposes that placental lineages emerged and diversified to fill niches left vacant after this catastrophe.
Did placental mammals evolved from marsupials?
Marsupial and placental mammals diverged from a common ancestor more than 100 million years ago, and have evolved independently ever since. This widespread evolutionary phenomenon is known as convergence.
What is convergent divergent and parallel evolution?
Convergent evolution is the opposite of divergent evolution, in which related species evolve different traits. Convergent evolution is similar to parallel evolution, in which two similar but independent species evolve in the same direction and independently acquire similar characteristics.
What is an example of convergent evolution in mammals?
Mammals. Several groups of ungulates have independently reduced or lost side digits on their feet, often leaving one or two digits for walking. That name comes from their hooves, which have evolved from claws several times. For example, horses have one walking digit and domestic bovines two on each foot.
How are marsupials and placentals examples of convergence?
CONVERGENCE: MARSUPIALS AND PLACENTALS Marsupials in Australia and placental mammals in North America provide another example of conver- gent evolution. These two subclasses of mammals have adapted in similar ways to a particular food supply, locomotor skill, or climate.
How are marsupials and placental mammals adapted to live?
They are adapted for a life underground, with virtually useless eyes and huge claws for digging. Examples of convergent evolution are widespread, not just in marsupials and placental mammals, but in many species of plants and animals across the world.
How did marsupials and placentals join South America?
South America joined to North America as recently as 3 mya, through a land bridge, the Isthmus of Panama. Placental mammals invaded South America and replaced many marsupial species. Over 200 species of marsupials live in Australia, along with many fewer species of placentals.
When did placental mammals diverge from the common ancestor?
Placental mammals, which have offspring that undergo gestation within the uterus and are born fairly advanced, and marsupials whose offspring are born very immature and continue to develop within a pouch on the mother’s body, diverged from a common ancestor around 100 million years ago.