The grasslands of Barsoom

I've just finished rereading The Legacy of Heorot by Larry Niven, Jerry Pournelle and Steven Barnes. It was actually better than I remembered. As my girlfriend (who is both wise and beautiful) says, it's a great little action-adventure SF story. But I have one little nitpick, which is actually common to a lot of other SF, both of the hard and soft varieties.

A brief synopsis: A band of 200 colonists has travelled in cryogenic suspension to a nearby habitable, earthlike planet and established a colony on an island. They are attacked by a strange critter they call a grendel - built like a Komodo dragon, it can move as fast as a cheetah, bite like a shark and has tail spikes like a stegosaurus.

The colonists kill the first critter after losing some of their number, then slaughter every one of the creatures on their island. But they didn't understand the grendel reproductive cycle. The fish-like critters in ponds and rivers are actually immature grendels, tadpoles of a sort. By removing all the adult grendels, the colonists have sent a signal for every one of the thousands of juvenilles to grow up into fierce adults. And the final battle is on.

My nitpick doesn't concern the grendels, which are great creations. They can supercharge their blood with an oxidizer that lets them move like the Flash, but also overheats them, forcing them to stay near cold water. And their reproductive strategy is based on real Earth animals.

The problem is with the background biology, which is simplistic and essentially a rip off of Earth's.

The planet of Avalon has grass, flowering plants, bushes with berries and fruits and trees, small mammal-like critters and flying pterosaur-analogues. All of the plants are primarily green, apparently using chlorophyl to photosynthesize. But how likely is it that we'll find all those things on any planet?

How long has grass, that ubiquitous plant, been around on Earth? Maybe 30 million years. The producers of the Walking With Dinosaurs and Walking with Prehistoric Beasts series have bemoaned the fact that they couldn't film anywhere with grass for any of the Mesozoic segments, and about half of the Tertiary segments. And grasses evolved from flowering plants, which didn't turn up until the late Jurassic, and didn't become common until the mid-Cretaceous.

There's a fabulous article that goes into all this in much more detail, along with the origins of a terribly addictive South American plant, here.

On another world, the notion that the gymnosperm to flowering plant to grass transition would happen exactly as it did here is fairly absurd. There would likely be whole plant-like species that wouldn't correspond to any known family. And why would they be green? If they struck on a molecule a bit better than chlorophyl (plants only convert about 2 per cent of the sun's light to energy) they would be dominant on their world - in shades of red, blue, orange or purple, perhaps.

So it's particularly galling to read a hard science fiction novel that so lovingly creates an alien animal, but ignores the other elements of the alien biosphere. Sure, it may be that Niven, Pournelle and Barnes just wanted to get on with the meat of their story, and who can fault them for that? But a few elements of the story betray a lack of understanding of the randomness of evolution.

In one chapter, a scientist character has trapped a few furry, mink-like critters, and decides that because they are fur covered and look like mammals, they most likely nurture their young with milk. But there's no reason to expect that on another planet, it won't be the scaly, lizard-looking creatures that give birth to live young and suckle them, and the furry ones that lay eggs and then run off, leaving their offspring to fend for themselves. A few advantagous mutations here, a bit of chance there, and wild combinations are possible.

I'm now looking forward to reading Beowulf's Children, the book's sequel. If I remember correctly, it includes a lot of interesting animals as the characters explore their planet's mainland.