  Thanks to the recent availability of comprehensive and detailed online
databases of startup companies, it has become possible to more directly
investigate startup ecosystems i.e. startup populations in specific regions. In
this paper, we analyze the emergence of 20+ such ecosystems in Europe and the
USA, with a specific focus on their sectoral diversity. Analyzing the sectoral
landscapes of these ecosystems using a new visualization tool indeed highlights
marked differences in terms of diversity, which we characterize using metrics
derived from ecological sciences. Numerical simulations suggest that the
emerging diversity of startup ecosystems can be explained using a simple
preferential attachment model based on sectoral funding.
