The possibilities of Life forming and evolving in a globular cluster is radically different than those of planets around individual (or binary) stars in the galactic plane (like ours).

#1: Globular clusters are almost as old as the Universe

Unlike the relatively short 5 billion years of existence of the Sun, all known globular clusters in the Milky Way galaxy age more than 10 billion years! Hosting smaller and dimmer stars that will still outlive all Sun-like stars, planets around them flourishing with Life becomes an intriguing possibility. Globular clusters are also void of big massive stars that whose supernovae/gamma ray bursts can cause mass extinctions.

#2: Globular clusters are ideal for Intelligent Life to evolve

The extremely short distances between the stars means that every other star is but a few light-weeks away. This presents an excellent opportunity for Intelligent civilizations to migrate to and colonize other star systems with relative ease. Being an Interstellar species is the way to ensure survival on the unforgivably large scales of space and time. Using the method of geometric progression, the entire globular cluster can be colonized within a few thousand years. This has implications for detecting Intelligent Life in a globular cluster, which can be tested relatively easily.

#3:Globular clusters are unlikely to host earth-like planets

Not all is good about the globular cluster environment though. All stars in a globular cluster are metal-poor, meaning lacking considerably in heavier elements like silicon, iron and magnesium. Terrestrial planets like the Earth are built from these heavy elements, thereby decreasing the possibility of their very formation. So it might be that globular clusters are really mostly void of terrestrial planets, leaving slim chances for Life to form and evolve.

#4: Our searches for planets in globular clusters have been unsuccessful

The Hubble Space Telescope (HST) performed the largest survey till date to find planets in a globular cluster. 34,000 stars of the massive cluster 47 Tucanae were looked for planets but Hubble found nothing. Later though, PSR B1620–26 b became the first planet (and the only one yet) to be discovered in a globular cluster (M4).