This paper presents an analysis of the time history of speckle patterns (THSP) that is one of the most used procedures to evaluate the biological activity by biospeckle images. THSPs generated by numerical simulations, obtained in a controlled drying of paint experiment and in dead and alive bean seeds under laser illumination were evaluated. We used first- and second-order statistics of the dynamic speckle patterns for different time and spatial amounts of data. We have tested both square and rectangular windows in the space time domain. The results show the agreement with a theoretical curve and comparisons between different window sizes.