Aurora - a critique by Stephen Baxter and others

[stevebowers]

But each one of those is a huge task, miles more difficult than building an interstellar rocket.

Building a interstellar rocket large enough to carry a complete biome is hard, because you soon come up against some very restrictive physical limits. However biological technology will continue to advance in the meantime, and by the time the first interstellar missions are ready there will have been some remarkable advances in biotech. Much of this tech would be honed in the space habitats that will already exist in the Solar System.

I think the first colony ships would probably carry very small, simplified biomes designed for the purpose, or species which have been designed to be easily gestated on arrival, or both. Wolves and bears might not make it (unless provolved wolves and bears take them along as pets, perhaps).