Believe it or not, some kangaroos live in trees! Would an intelligent designer do this to a poor plains-dwelling kangaroo? Perhaps to make up for their awkward living accommodations, God made them irresistibly cute! Some thoughts on what evolutionary changes may be in store for the tree kangaroo follow.
Tree Kangaroo Picture, click here.
Aren’t they cute? In some poses, they resemble a chunky cat. Maybe that is because cats are somewhat adapted for climbing. In their spare time, tree kangaroos pose for toy makers.
Kangaroos are marsupials, an early-evolved form of mammal. Kangaroos and similar animals are known for having big feet and hopping. Their big, narrow and long, feet are adapted to locomotion on grassy plains. The plains-dwelling kangaroos cannot walk! They have to hop! At low speeds, this is not very energy efficient, but at 10 km/hr and faster, they recover energy from leg tendons that stretch and rebound during hopping.
Kangaroos evolved from (p. 58 ff.) a (cute) marsupial something like the living pygmy possum, an Australia native that shares some unusual features with the kangaroo. The kangaroo ancestor, unlike the pygmy possum, was arboreal–lived in trees. They evolved into ground-dwelling kangaroos during the Eocene Epoch, roughly 45 million years ago. Although their unique foot evolved very early in their history, it was later that hopping evolved.
Tree kangaroos (also see: tree kangaroos) live in Australia, New Guinea, and nearby islands. They are about two feet (70 cm) tall and weigh about 25 pounds (11 kg). The 12 or so species of tree kangaroos have a hand-over-hand, foot-over-foot gait; they don’t have to hop. Along with well developed front claws and a big tail for balance, this makes them agile climbers. They evolved from ground-dwelling kangaroos who returned to life in the trees. It is unknown whether the parent species hopped or walked and ran.
Although they are comfortable on the ground, tree kangaroos are quite skilled arborealists. They can leap from limb to limb over a distance of 20 ft. Their big tail helps them maintain balance while airborne. They also have the remarkable ability to jump to the ground from a height of 60 ft without being hurt!
It is interesting to look at other tree-dwelling animals and speculate about what might evolve from the tree kangaroo. What lives in trees now? Well, I can think of monkeys, chimpanzees, lemurs, tree sloths, squirrels including flying squirrels, sugar gliders. and Teletubbies. There are plenty more, from microscopic no-see-ems of all sorts to macroscopic insects, but these forms are not likely to be taken by kangaroos in the foreseeable future. It is noteworthy that birds and bats frequent trees.
With their herbivorous (vegetarian) diet and climbing and leaping skills, tree kangaroos seem to occupy the same ecological niche as monkeys and lemurs. It may be that tree kangaroos are so well adapted to this niche that there is no room for new animal forms (probably at the Family level) to evolve in it. More species of tree kangaroo may be possible in this niche. On the other hand, their rear feet don’t look optimal for living in a tree. Monkeys, chimps, lemurs, and sloths all have proportionately smaller, hand-like rear feet. Maybe the tree kangaroo will enter new ecological niches by adaptive radiation.
It looks like there are a couple of avenues open for further adaption to life in the trees. Tree kangaroos might go the “slow” route and develop hanging around to a high art, as sloths have done. Or, they could go “fast” and become the flying squirrel and sugar glider of the future. Leaping, as they do, from tree to tree and 60 ft to the ground, it sure seems like some built-in parachuting would lend a competitive advantage. Since they don’t have feathers, further evolution into a bird is quite unlikely, but what comes next after flying squirrel or sugar glider? Might they not evolve into bat-like creatures? I wonder if they would still be cute?
And can it be far from flying squirrel, sugar glider, and bat to PTEROSAUR?
Evolution is undirected, and consequently, cannot be predicted. It might not even be predictable if we had full knowledge of environmental conditions and evolutionary mechanisms. Chance just might have too large a role.
The undirectedness of evolution gives many creationists a problem. They want to believe that their lives are looked over (they might say “shepherded”) by a loving God who is in control of the Universe. The thought that human beings evolved from an ape-like ancestor by chance, rather than being created from the dust of the earth, is disturbing to them.
I doubt that creationists look to the future to wonder what people could evolve into. Our ancestors may have come down from the trees to the African plains. Like the tree kangaroo, we may develop strong arms with long claws, a large tail, and an irresistible cuteness, and return to the trees!
(But I like tree kangaroos!)